Introduction
Dengue is widespread in South-East Asia, the Indian sub-continent, the Pacific region as far south as Queensland in Australia, the Caribbean Islands, northern and eastern parts of Central and South America, to a lesser extent the Middle East and sporadically in Africa. Outbreaks are common and often occur after the rainy seasons when mosquitoes breed more actively.

The cause is an virus spread by the Aedes aegypti species of mosquitoes which predominantly bite during the day.

The Illness
After an incubation phase of 3-8 days there is usually a sudden onset of fever, headache, muscle and joint pains. A rash may develop. Within a few days the illness usually resolves and serious complications are uncommon. In a few cases dengue can progress to a haemorrhagic form, with shock, which can be fatal.

Treatment
There is no specific anti-viral treatment. Symptoms like headache and fever can be treated symptomatically. Hospital care is indicated in severe illnesses or if complications occur.

Recommendations for Travellers
Avoid mosquito bites, use insect repellents, and seek medical attention for feverish illness if you have been in an area where dengue is present. A vaccine is under trial but not yet available.

History
The word "dengue" is a Spanish adaptation of the Swahili phrase "ki denga pepo", meaning "cramp-like seizure caused by an evil spirit". It emerged during a Caribbean outbreak in 1827-1828.

The first case report dates back from 1789 and is attributed to Benjamin Rush, who coined the term "breakbone fever" (because of the symptoms of myalgia and arthralgia). The viral etiology and the transmission by mosquitoes were only deciphered in the 20th century. The socioeconomic impact of World War II resulted in increased spread globally.